Perforating equipment for perforating webs of sheet materials such as stamps have typically used a rotary perforating wheel with a plurality of perforating pins to punch perforations in a web material.
Recently, it has been considered desirable to affix individual postage stamps to solicitations and other mass mailings instead of using metered mail or other forms of postage. The reasoning is that the recipient is likely to view a stamped envelope as a more personalized letter. The affixing of the individual stamps to a mass mailing is generally automated. The equipment typically receives a roll of stamps. The stamps are conveyed by a roller having pins that fit into the perforations to engage the stamp roll and convey it in the equipment. The equipment separates each stamp from the adjacent stamp by separating successive stamps from the stamp roll at a perforation line. This roller has been found to be very sensitive to variations in the distance between perforation lines. The equipment input may become fouled when the roller pins do not engage and convey the stamp.
The separation of successive stamps should occur along each perforation line between adjacent stamps. However, since the equipment is designed for and operated on the assumption that the perforation lines are of uniform distance, variations in the distance between perforation lines may cause the cut edges to become out of register with the stamp perforation edges. This can cause additional registration and alignment problems if the equipment is unable to process the misaligned stamps. Potentially, the equipment output may also become fouled. Thus, with variations in the distance in the perforation lines, the entire stamping operation may have to be halted, the stamp coil relocated, and the faulty stamps replaced. This creates considerable expense if large numbers of stamps must be discarded.
It would be desirable to provide an apparatus and method capable of providing consistently precise perforation lines of an exact distance.